Catalysis Today, Vol.79, No.1-4, 487-494, 2003
The Claus process: teaching an old dog new tricks
The potential of integrating reaction with adsorption in a single piece of equipment to favourably displace chemical equilibria has attracted considerable attention in recent years. In contrast to the most such multifunctional reactor concepts investigated so far, the aim of our work is to study an industrially relevant chemical system with all its peculiarities. The feasibility of enhancing conversion in fixed-bed adsorptive reactors has been evaluated for the Claus reaction used in sulphur recovery. which is usually carried out in a multistage process, to counteract the severe equilibrium limitations at high conversions. Both experimental and simulation results indicate that the adsorption/reaction kinetics and the adsorbent capacity have to exhibit appropriate and compatible values in order to overcome the equilibrium limitation and attain high conversions in a single-step process. A crucial point is the selection of suitable reaction conditions, since the occurrence of undesirable side-reactions (e.g. suppression of COS elimination in the case of the Claus process) may be amplified by the distorted concentration profiles in adsorptive reactor operation. In industrial applications such by-products may be of particular importance and thus exert a decisive influence on the concentration profile modifications possible. (C) 2003 Elsevier Science B.V. All rights reserved.
Keywords:multifunctional reactor;adsorptive reactor;claus process;sulphur recovery;adsorption;zeolites